Wyo. Stat. § 1-26-702: Compensation for taking.

(a) Except as provided in subsection (b) of this section, the measure of compensation for a taking of property is its fair market value determined under W.S. 1-26-704 as of the date of valuation.

(b) If there is a partial taking of property, the measure of compensation is the greater of the value of the property rights taken or the amount by which the fair market value of the entire property immediately before the taking exceeds the fair market value of the remainder immediately after the taking.